monatomic ions - a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons, respectively

polyatomic ions - ions composed of more than one atom (often end in -ite or -ate)

binary compound - composed of two elements and can be either ionic or molecular, must be named with the cation name followed by the anion name

acid - a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water

base - an ionic compound that produces hydroxide ions when dissolved in water, same naming convention as other ionic compounds

law of definite proportions - in samples of any chemical compound, the masses of the elements are always in the same proportions and because atoms combine in simple whole-number ratios, it follows that their proportions by mass must always be the same

law of multiple proportions - whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers